The present invention relates generally to self-coupling strapping devices that may be referred to as tie straps, cable ties, zip ties, tie wraps, wire ties, and so on, whose many uses may include securing objects in place, bundling objects together, and tying bags closed. Tie straps generally comprise an elongated flexible strap extending from a stout retaining head. Disposed on the strap are usually a plurality of axially oriented ridges adapted to couple with a head retaining mechanism (e.g. retainer). Common retainers include a slot through which the strap may be inserted or a pawl under which the strap may be disposed.
Many variations exist, for example flat straps with raised or depressed ridges on one or more surfaces, small-diameter string-like straps on which multiple separated large-diameter cylinders or spheres are disposed, elastomeric (compressible) straps and retainers, and so on. Defining physical attributes of tie straps are: (1) a strap comprising a plurality of alternating regions of large and small cross-sectional areas, e.g. major and/or minor dimensions for a polygonal cross section such as a rectangle; and (2) a retainer that couples with one or more large- or small-dimension strap regions.
Correspondingly, there are many strapping devices that are not considered tie straps, such as: (1) ratchet straps and tie downs whose strap cross-sectional dimensions are substantially uniform along the longitudinal axis and whose retainer couples with such uniform strap primarily via friction, compression, or wrapping; (2) power-cord wraps and fasteners whose strap and retainer include complementary hook-and-loop regions (e.g. Velcro); and (3) power-cord wraps and fasteners whose strap includes one or more keyholes and whose retainer includes one or more buttons (or vice versa).
Single-use tie straps have existed for over a century, for example U.S. Pat. No. 588,848, entitled “Bag-fastener,” and more recently U.S. Pat. No. 2,979,794, entitled “Wire or Cable Bundle Tie.” Although such tie straps are useful for many applications, there is a need for reusable tie straps and for tie straps that may be arbitrarily tightened and loosened. Consequently, multiple-use tie straps with releasable retainers have been developed, for example U.S. Pat. No. 4,991,265, entitled “Cord Tie Device” and U.S. Pat. No. 5,193,250, entitled “Releasable Cable Tie.” Advancements in elastomeric materials broadened the mechanisms by which straps and retainers could readily couple and decouple with each other, for example U.S. Pat. Nos. 7,866,005 and 8,276,244, both entitled “Elastomeric Releasable Cable Tie,” and U.S. Pat. No. 9,021,665, entitled “Elastic Zip Tie.”
Tie-strap reusability is a salient attribute of many prior arts and of the present invention. However, the present invention solves a critical need whose solution has not yet been taught: that a single tie strap may simultaneously achieve semi-permanent and reusable strapping. “Strapping” is coupling of a strap with a retainer; “reusable strapping” is strapping that is readily coupled and decoupled; and “semi-permanent strapping” is strapping that may or may not be readily coupled or decoupled. Simultaneous reusable and semi-permanent strapping allows a tie strap to be semi-permanently strapped to a first object (or objects), for example a stationary post, while a second second object (or objects) may be reusably strapped thereto, for example the handle of a broom. In the immediate example, the tie strap may be strapped to the post for an extended duration while the broom may be repeatedly strapped thereto while not in use. Similarly, such a tie strap may be used to strap an object to itself. For example, a tie strap may be semi-permanently strapped to an end of the a power cord and reusably strapped around additional loops of the cord when stowed.
U.S. Pat. No. 6,317,933, entitled “Binding Band” and U.S. Pat. No. 6,588,074, entitled “Self-mating Reclosable Binding Strap and Fastener” teach a slotted retainer adapted to receive a strap for securement to a first object and a hook-and-loop (or hook-and-hook) fastener for securement to a second (or same) object. However, a primary disadvantage of hook-and-loop fasteners is the loss of fastening strength due to soiling or wear. Furthermore, U.S. Pat. No. 6,523,229, entitled “Cord Keeper Strap” teaches a strap with keyholes and a retainer comprising a slot to receive the strap for securement to a first object and a button to receive the strap for securement to a second (or same) object. However, primary disadvantages of button-and-keyhole fasteners include fracturing of the strap adjacent to a keyhole, unreliable coupling between button and keyhole, and long distances between adjacent keyholes that yields coarse adjustment steps.